Density control apparatus for roll winding machine



Oct. 18, 1966 ARTERTQN ET AL 3,279,718

DENSITY CONTROL APPARATUS FOR ROLL WINDING MACHINE Filed Jan. 18, 1965 AMPLIFIER Bu HYDRAULIC INVENTORS ALFRED A. ARTERTON ROBERT DAVEE ATTORNEY United States Patent 3,279,718 DENSITY CONTROL APPARATUS FOR ROLL WINDING MACHINE Alfred A. Arterton, Whitinsville, and Robert Davee, Northboro, Mass, assignors to Hobbs Manufacturing Company, Worcester, Mass., a corporation of Massachusetts Filed Jan. 18, 1965, Ser. No. 426,273

12 Claims. (Cl. 24267.1)

This invention relates to control of the density of a roll of the type which includes a web Wound a plurality of times on a core. The principal object of the present invention is to control the roll density over a wide range. It is well known that difficulties are encountered in maintaining roll densities uniform especially in the high speed winding of plastic webs and also in light weight fibrous materials. The present invention therefore provides means for accurately controlling this density while at the same time making it possible to use very light tension on the web.

Further objects of the invention include the provision of the control means in which the contact pressure between a surface roll and the winding roll itself is accurately programmed with relation to the torque utilized on the core of the winding roll; and the provision of a control device of the class described in which the density of web materials can be repeated accurately over a wide range of materials and pressures.

A further object of the invention resides in the provision of a density control apparatus for a roll winding machine in which a core on which the web is to be wound is mounted in a fixed position and is driven under conditions of programmed torque to wind the web thereon, the web being trained over a surface roll substantially in contact with the material being wound on the core, said surface roll being mounted on a movable carriage and including means for holding the surface roll in balanced condition by gradually moving the carriage away from the core as the diameter of the roll increases; and the provision of means mounting the surface roll on the carriage for limited motion under influence of the expanding diameter of the roll being wound, together with means sensing this motion, the sensing means then energizing a power unit for moving the carriage in a direction away from the roll, thus maintaining the surface roll in balanced predetermined pressure contact with respect to the roll being wound.

A further object of the invention resides in the provision of the movable surface roll above referred to in combination with the fixed position core wherein the relative motion of the surface roll with respect to the carriage can be programmed by means of a cam which is adjustably mounted but in a fixed position and operating against a regulator which is mounted in turn on the carriage. As the roll diameter increases, air pressure means acting against the surface roll mounting means is altered, depending upon the relative position of the cam and the carriage, in order to program the respective pressures; and thus the control apparatus includes means maintaining a predetermined force between the surface roll and the winding roll. By this method and apparatus, very low forces may be maintained and the pattern may be repeated from roll to roll so that any roll of any given material may be wound to the same extent and with the same density.

Other objects and advantages of the invention will appear hereinafter.

In the drawing the figure shows a diagrammatic representation of the apparatus and method utilized in the present invention.

The reference numeral '10 indicates a core upon which a web W is to be wound. This core is provided with 3,279,718 Patented Oct. 18, 1966 a center assist drive torque which is programmed as will be hereinafter described. This core may be mounted and supported in any way desired by means well known to those skilled in the art, and insofar as the present invention is concerned, the principal attribute of this core is that it does not move except to rotate on a fixed axis.

The reference numeral 12 indicates a carriage mounted on tracks or ways 14 fixed with relation to a supporting surface 16. This carriage is movable as through a hydraulic cylinder 18 having a fixed reference point with respect to a fixed wall at 20 by means of a piston rod or the like 22. On the carriage there is an electric amplifier controlling a hydraulic unit of well known description and this is indicated in general by the reference numeral 24. This controls the hydraulic cylinder 18 so as to move the carriage along the track or ways 14.

On the carriage 12 there is an upright standard or the like 26 and preferably this is provided with an overhead arm or the like which may be fixed with relation thereto and as indicated at 28 for motion with the carriage. Suspended from the overhead arm 28 there are a pair of spaced brackets 30 pivotally mounting as on an axis which is indicated at 32 a pair of depending arms 34. On these arms intermediate the ends thereof there is mounted on an axle indicated at 36 a surface roll 38; and a motor (not shown) is provided for driving this shaft and therefore the surface roll 38 in the direction of the arrow.

At the bottom or lower end of each arm 34 there is provided a signal arm 40 fixed with relation thereto and movable therewith about the axis 32. A pair of stops 42, 42 may be provided on the carriage mounted in any way desired in order to limit the degree of swing of the arms 34. At the lower end of the arm 40 there is a flag 44 which is adapted to move with relation to a signaling device generally indicated at 46. This signaling device is also mounted on the carriage to move therewith and may be in the nature of a photocell or any kind of a transducer for the purpose of controlling the amplifier and hydraulic unit 24. It will be seen that this signal is amplified by reason of the distance of the arm 44 from the pivot axis 32 as compared with the distance of the axle 36 from this axis.

Each of the spaced arms 34 is provided with a pneumatic or similar air cylinder at 48 having a plunger or the like bearing on its respective arm and resisting the thrust of such arm in a clockwise direction. These cylinders are controlled through a regulator 50 for increasing or decreasing the pressure on the arms 34, the regulator as well as the pneumatic cylinders 48 being mounted on the standard 46 to move with the carriage.

The regulator 50 however is controlled by a longitudinal cam 52 which is mounted for instance on a part of the framework 20 in fixed relation. This cam can be replaced by cams of'ditferent contour or it can be adjusted at each end thereof in order to vary its inclination with respect to a horizontal. The result of this is that the pressure exerted by the pneumatic cylinders 48 on the arms 34 is programmed as the regulator moves to the left with its feeler stem 54 in contact with the cam 52.

It is clear that many of the details of this apparatus may be varied within the scope of the invention and can be provided by those skilled in the art without difficulty.

Assuming an empty core to be placed in the winding position, see core 10, the web W is then threaded over the surface roll being attached to the core in any way desired. The surface roll is advanced toward the core by means of the hydraulic cylinder moving the carriage to the right until the surface roll contacts the core. As the contacting force between the surface roll and core reaches that being delivered by the pneumatic cylinders at 48, the

roll support arms 34 are forced to the left off of the forward stop. This motion is picked up by the signaling device 46, transferred to the amplifier and hydraulic unit 24 and energizing the hydraulic cylinder to move the carriage so that the flag at 40 will then depend once more midway between the two stops 42, thus maintaining the system in balanced condition with the surface roll pressure against the core being that which is provided by the pneumatic cylinders 48.

The drive torque control of the core now being energized, the winding proceeds and the diameter of the winding roll increases. This of course has the effect of forcing the surface roll once more to move in a clockwise direction and then again through the flag 40, sensing device 46, etc., the carriage is caused to once more move maintaining the system in balance.

A predeterniined force is therefore maintained between the surface roll and the winding roll but this force is varied according to the position or adjustment of the cam 42 acting on the regulator 50 for the air cylinders 48. By this method very low forces may be maintained because by virtue of the control apparatus described the in- .herent friction of the carriage system is overcome and the pattern of the roll winding may be repeated from roll to roll. In addition the contact force may also be programmed from core to full diameter over a wide range of patterns.

In addition to the above, there may also be utilized an electric signal again taken from the position of the carriage to vary the control of the DC. center assist motor drive to the core 10. By adjusting the amount of the signal change which goes into the control the torque change relative to roll diameter change is regulated and therefore the torque versus roll diameter pattern may also be varied from practically constant torque to any degree of increasing torque which is limited only by the material being wound.

It is preferred that the two arms 34 be not connected in any way except by the axle 36 but at the same time it is to be noted that the regulator 50 and its governing cam 52 are included only in a single unit controlling both of the air cylinders 48 so that the pressure at each end of the surface roll is always maintained equal. However this allows slight variations in web density and thickness at any particular instant to be accommodated without interfering in any way with the operation of the machine.

Although the specific details of all of the parts of the machine have not been specifically shown, it is believed that anyone skilled in the art will be able to carry out the construction and operation to their own satisfaction and it is also pointed out that the deficiencies of the prior art and the problems involved in the winding of light weight plastic or fibrous materials are so well known as to need no recapitulation. Attention is drawn to British Patent 932,151, published July 24, 1963, in which certain shortcomings of the prior art and the problems involved in winding of certain materials are extensively set forth.

What is claimed is:

-1. Density control apparatus for a roll winding machine comprising a relatively fixed position rotating core on which a web is to be wound, a surface roll over which the web is trained prior to winding on the core, a carriage, means to move the carriage in a direction transverse to the axis of the core, the surface roll being mounted to move with the carriage and having an axis generally parallel to that of the core, means on the carriage mounting the surface roll for limited motion relative to the carriage and to the core under influence of the expanding diameter of the wound core, means sensing the limited motion of the surface roll relative to the carriage, and means to actuate the carriage moving means, the sensing means energizing the actuating means.

2. The density control apparatus of claim 1 including means resisting the motion of the surface roll relative to the carriage.

3. The density control apparatus of claim 1 including adjustable means resisting the motion of the surface roll relative to the carriage.

4. The density control apparatus of claim 1 including means resisting the motion of the surface roll relative to the carriage, and means to adjust the degree of resistance thereof.

5. The density control apparatus of claim 1 including means resisting the motion of the surface roll relative to the carriage, and means to adjust the degree of resistance thereof including a fixed position cam and a cam follower movable on the carriage relative to the cam.

6. The density control apparatus of claim 1 including means resisting the motion of the surface roll relative to the carriage, said last-named means being pneumatic.

7. The density control apparatus of claim 1 including means resisting the motion of the surface roll relative to the carriage, said last-named means being pneumatic, and means to adjust the thrust thereof, said thrust adjusting means including an air regulator, a stem to vary the same, and a fixed position cam, the regulator and its stem being mounted to move relative to the cam according to the carriage motion.

8. The density control apparatus of claim 1 including means on the carriage mounting the surface roll.

9. The density control apparatus of claim 1 including means on the carriage mounting the surface roll compris ing a depending pivoted arm.

10. The density control apparatus of claim 1 including means on the carriage mounting the surface roll comprising a depending pivoted arm swingably mounted adjacent its upper end on the carriage. Y

11. The density control apparatus of claim 1 including means on the carriage mounting the surface roll comprising a depending pivoted arm swingably mounted adjacent its upper end on the carriage, the surface roll being journaled in the arm intermediate the ends thereof.

12. The density control apparatus of claim 1 including means on the carriage mounting the surface roll comprising a depending pivoted arm swingably mounted adjacent its upper end on the carriage, the surface roll being journaled in the arm intermediate the ends thereof, and an extension on the arm adjacent the lower end thereof, in cooperative relation to the sensing means, said extension magnifying the motion of the surface roll relative to the carriage.

References Cited by the Examiner UNITED STATES PATENTS 2,196,000 4/ 1940 Richardson 242- 3,157,371 11/1964 Billingsley 24256.2

FRANK I. COHEN, Primary Examiner.

G. F. MAUTZ, Assistant Examiner. 

1. DENSITY CONTROL APPARATUS FOR A ROLL WINDING MACHINE COMPRISING A RELATIVELY FIXED POSITION ROTATING CORE ON WHICH A WEB IS TO BE WOUND, A SURFACE ROLL OVER WHICH THE WEB IS TRAINED PRIOR TO WINDING ON THE CORE, A CARRIAGE, MEANS TO MOVE THE CARRIAGE IN A DIRECTION TRANSVERSE TO THE AXIS OF THE CORE, THE SURFACE ROLL BEING MOUNTED TO MOVE WITH THE CARRIAGE AND HAVING AN AXIS GENERALLY PARALLEL TO THAT OF THE CORE, MEANS ON THE CARRIAGE MOUNTING THE SURFACE ROLL FOR LIMITED MOTION RELATIVE TO THE CARRIAGE AND TO THE CORE UNDER INFLUENCE OF THE EXPANDING DIAMETER OF THE WOUND CORE, MEANS SENSING THE LIMITED MOTION OF THE SURFACE ROLL RELATIVE TO THE CARRIAGE, AND MEANS TO ACTUATE THE CARRIAGE MOVING MEANS, THE SENSING MEANS ENERGIZING THE ACTUATING MEANS. 